Restkit mapping arrays to core data - ios

Question

I have the following JSON:
{
    "id": 1,
    "editable": true,
    "number": "1",
    "name": "Text here",
    "banner": "Text here",
    "address": "Text here",
    "city": "Text here",
    "contact": "Text here",
    "latitude": "Text here",
    "longitude": "Text here",
    "banner_id": 5,
    "hours": [
        {
            "day": "monday",
            "start": "8:00am",
            "end": "5:00pm"
        },
        {
            "day": "tuesday",
            "start": "",
            "end": ""
        },
        {
            "day": "wednesday",
            "start": "",
            "end": ""
        },
        {
            "day": "thursday",
            "start": "",
            "end": ""
        },
        {
            "day": "friday",
            "start": "",
            "end": ""
        },
        {
            "day": "saturday",
            "start": "",
            "end": ""
        },
        {
            "day": "sunday",
            "start": "",
            "end": ""
        }
    ]
}
I am trying to create a mapping of this object which contains an array of hours, my code is as follows:
RKObjectMapping* hoursMapping = [RKObjectMapping mappingForClass:[Hours class] ];
[hoursMapping addAttributeMappingsFromArray:#[ #"day", #"start", #"end"]];
RKObjectMapping* storeMapping = [RKObjectMapping mappingForClass:[Store class] ];
[storeMapping addAttributeMappingsFromArray:#[ #"id", #"editable", #"number", #"name", #"banner", #"address", #"city", #"contact", #"latitude", #"longitude", #"banner_id"]];
[storeMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:#"hours"
toKeyPath:#"hours"
withMapping:hoursMapping]];
RKResponseDescriptor *storeResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:storeMapping
method:RKRequestMethodAny
pathPattern:#"api/v2/stores.json"
keyPath:#""
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
The mapping fails and the only error returned says:
"The operation couldn't be completed"
What am I doing wrong here? How can I get this to map successfully?
Store.h
#interface Store : NSManagedObject
#property (nonatomic, retain) NSNumber * id;
#property (nonatomic, retain) NSNumber * editable;
#property (nonatomic, retain) NSString * number;
#property (nonatomic, retain) NSString * name;
#property (nonatomic, retain) NSString * banner;
#property (nonatomic, retain) NSNumber * address;
#property (nonatomic, retain) NSString * city;
#property (nonatomic, retain) NSString * contact;
#property (nonatomic, retain) NSString * latitude;
#property (nonatomic, retain) NSString * longitude;
#property (nonatomic, retain) NSNumber * banner_id;
#property (nonatomic, retain) NSSet *hours;
#end
#interface Store (CoreDataGeneratedAccessors)
- (void)addHoursObject:(Hours *)value;
- (void)removeHoursObject:(Hours *)value;
- (void)addHours:(NSSet *)values;
- (void)removeHours:(NSSet *)values;
#end
Hours.h
#interface Hours : NSManagedObject
#property (nonatomic, retain) NSString * day;
#property (nonatomic, retain) NSString * start;
#property (nonatomic, retain) NSString * end;
#end

Answer 1

For anyone trying to find a solution to this problem:
The problem was that I was using an Object Mapping with Core Data.
I changed all references to an Object Mapping into Entity Mappings instead. The relationship mapping is the same but now points to the Core Data entity instead of the class. Now everything works as expected.
RKEntityMapping *storeMapping = [RKEntityMapping mappingForEntityForName:#"Store" inManagedObjectStore:managedObjectStore];
storeMapping.identificationAttributes = #[#"id"];
[storeMapping addAttributeMappingsFromArray:#[ #"id", #"editable", #"number", #"name", #"banner", #"address", #"city", #"contact", #"latitude", #"longitude", #"banner_id"]];
RKEntityMapping *hoursMapping = [RKEntityMapping mappingForEntityForName:#"Hours" inManagedObjectStore:managedObjectStore];
[hoursMapping addAttributeMappingsFromArray:#[#"day", #"start", #"end"]];
[storeMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:#"hours" toKeyPath:#"hours" withMapping:hoursMapping]];
RKResponseDescriptor *storeResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:storeMapping
method:RKRequestMethodAny
pathPattern:#"/api/v2/stores.json"
keyPath:#""
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptor:storeResponseDescriptor];
For more information visit: https://medium.com/ios-os-x-development/restkit-tutorial-how-to-fetch-data-from-an-api-into-core-data-9326af750e10